DFA-1□□□ isolated safety barrier is an auxiliary unit of DDZ-III electric unit combination instrument.

Safety Barrier is key equipment for intrinsically safe explosion-proof instrument. In normal state, the safety barrier does not affect the normal operation of the system; when there is fault, safety barrier will limit voltage and current to limit electric energy within the limits of ignition and ensure the security. It is widely used in petroleum, chemical industry, light industry and other explosive flammable place.

Detecting terminal barrier is completed with two-wire transmitter and supply power for it. At the same time, it will restrict dangerous energy enter into dangerous place. Isolated safety barrier can convert 4～20mA DC signal from transmitter to isolated 4～20mA current signal or 1～5V voltage signal.

Operating safety barrier is usually completed with actuator. It is not only restrict dangerous energy enter into dangerous place but also isolate direct current signal.